A packaged engine working machine is known as a cogeneration apparatus in which a generator and/or a refrigerant compressor serving as working machine(s) are/is driven by an engine to perform electric power generation and/or heat pump air conditioning and to produce warm water by utilizing exhaust heat generated in electric power generation and/or heat pump air conditioning. Such a packaged engine working machine is adapted so that an engine, a working machine driven by the engine, and electrical components for the engine and the working machine are stored inside a package.
Electrical components used in a packaged engine working machine are stored in an electrical component box in order to prevent the electrical components from being exposed to heat and increased in temperature during engine operation.
For example, Patent Document 1 discloses an electrical component cooling apparatus for limiting temperature increase of electrical components such as a relay disposed inside an engine compartment of a vehicle.